Thread: 32mm kitchen laminate movement

In the last year or so I've made myself a router table and a Matthias Wandel inspired thickness sander; where the main surfaces are 32mm laminated kitchen bench seconds bought from a local manufacturer. These boards were flat when installed and with the unlaminated undersides and edges sealed. But they've since risen convex or sunk in a bowl shaped by a few mm and it's beginning to screw up my work.

Would I have been better off putting a couple of sheets of hi grade (marine) ply together for these surfaces instead, or is this just a natural effect of having a crappy workshop environment that changes dramatically with the seasons?

I'm happy to remake the surfaces but naturally don't want a repeat of what's been happening if I can avoid it. I'm not sure if a thinner torsion boxed surface would do, or if there is some other form of underside bracing that may help?

Any experienced thoughts? I pay well